Amblyopia is a dimness of vision in the absence of a demonstrable structural defect, and it may occur gradually or suddenly and may effect both eyes or one eye. Amblyopia is often difficult to diagnose, and especially so in pre-literate children. Since proper treatment of amblyopia can be dependent upon how early it can be detected, it is desirable to recognize amblyopia in pre-literate children as early as possible. In this way learning problems associated with the dimness of vision, particularly dimness of central vision, for pre-literate children can be overcome.
The invention relates to a method for screening pre-literate children for amblyopia and a simple screening device for use in accomplishing that purpose. The invention only relates to screening, and is not intended to provide positive diagnosis of amblyopia. However after screening according to the invention is practiced, those children without an amblyopic condition can be clearly identified, and any children falling outside of that category can be sent for more detailed testing. In this way unnecessary detailed testing of a large number of children is avoided, yet positive diagnosis of those having an amblyopic condition is facilitated.
The simple screening device according to the invention comprises no moving parts although an indicia-containing card forming part of the structure may be removable and replaceable if desired. A pair of eyepieces are mounted by a static structure which segregates the fields of view through the eyepieces and maintains a fixed static relationship between them. The indicia-containing card has a face thereof with two different, spaced indicia formed thereon, the indicia each being a pictorial representation of a common physical object or being, so that a preliterate child will have no difficulty in identifying the object. The card is either permanently or detachably mounted to the static structure so that each pictorial representation is visible through one of the eyepieces, but not the other.
The method of screening pre-literate children for amblyopia according to the present invention utilizes the simple screening device so that the card is placed in association with the eyepieces with one pictorial representation in the field of view through each eyepiece. The pre-literate child then looks into the eyepieces, one eye associated with each eyepiece, and reports what pictorial representations he or she sees. The report can be verbal, or the reporting sequence can be non-verbal if desired. In a nonverbal report the child would be asked merely to select from a number of pictures or tiles any objects he or she sees by looking into the eyepieces. For any child that does not accurately report both of the different pictorial representations contained on the card, more detailed testing is provided.
The present invention provides an extremely simple yet effective way for screening pre-literate children for amblyopia. No complicated apparatus or expensive equipment is provided. The invention merely employs a few static components, utilizes ambient light, and amblyopia screening utilizing the invention may be practiced in a matter of seconds for each child.
It is the primary object of the present invention to provide a simple, yet effective, method and apparatus for screening pre-literate children for amblyopia. This and other objects of the present invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.